EclipseLink class descriptor customizer that mimics Hibernate's ImprovedNamingStrategy for table and field naming

ImprovedNamingDescriptorCustomizer.java

public class ImprovedNamingDescriptorCustomizer implements DescriptorCustomizer {
    @Override
    public void customize(ClassDescriptor classDescriptor) throws Exception {
        String className = classDescriptor.getJavaClassName();
        String shortName = Helper.getShortClassName(className);
        String improvedName = toImprovedName(shortName);

        classDescriptor.setTableName(improvedName);

        updateMappings(classDescriptor, improvedName);

        for (DatabaseField field : classDescriptor.getPrimaryKeyFields()) {
            field.setName(toImprovedName(field.getName()));
        }
    }

    void updateMappings(ClassDescriptor classDescriptor, String improvedTableName) {
        for (DatabaseMapping mapping : classDescriptor.getMappings()) {
            if (mapping.isDirectToFieldMapping()) {
                DirectToFieldMapping directToFieldMapping = (DirectToFieldMapping) mapping;

                String newFieldName = directToFieldMapping.getFieldName().replaceAll(improvedTableName+".","");

                // If the field name is not overridden, then derive the column name from the attribute name
                if (newFieldName.toLowerCase().equals(directToFieldMapping.getAttributeName().toLowerCase())) {
                    newFieldName = toImprovedName(directToFieldMapping.getAttributeName());
                }

                directToFieldMapping.getField().setName(newFieldName);
                directToFieldMapping.getField().setTableName(improvedTableName);
            }
        }
    }

    String toImprovedName(String s) {
        String[] parts = s.split("(?<!(^|[A-Z]))(?=[A-Z])|(?<!^)(?=[A-Z][a-z])");

        StringBuilder sb = new StringBuilder();
        for (int i=0;i<parts.length;i++) {
            sb.append(parts[i].toLowerCase());
            if (i+1 < parts.length) {
                sb.append("_");
            }
        }

        return sb.toString();
    }
}

MyEntity.java

@Entity
@Customizer(ImprovedNamingDescriptorCustomizer.class)
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    // Column *will not* be overridden since it is explicitly defined here.
    @Column(name = "FOO")
    private boolean deleted;

    // ... getters & setters
}